BCM4354 Data Sheet
WLAN Radio Subsystem
Section 12: WLAN Radio Subsystem
The BCM4354 includes an integrated dual-band WLAN RF transceiver that has been optimized for use in
2.4 GHz and 5 GHz Wireless LAN systems. It has been designed to provide low-power, low-cost, and robust
communications for applications operating in the globally available 2.4 GHz unlicensed ISM or 5 GHz U-NII
bands. The transmit and receive sections include all on-chip filtering, mixing, and gain control functions.
Sixteen RF control signals are available (eight per core) to drive external RF switches and support optional
external power amplifiers and low-noise amplifiers for each band. See the reference board schematics for
further details.
A block diagram of the radio subsystem (core 0) is shown in Figure 32 on page 82. Core 1, is identical to Core 0
without the Bluetooth blocks. The integrated on-chip baluns (not shown) convert the fully differential transmit
and receive paths to single-ended signal pins.
Receiver Path
The BCM4354 has a wide dynamic range, direct conversion receiver that employs high order on-chip channel
filtering to ensure reliable operation in the noisy 2.4 GHz ISM band or the entire 5 GHz U-NII band. An on-chip
low noise amplifier (LNA) in the 2.4 GHz path in core 0 is shared between the Bluetooth and WLAN receivers,
whereas the 5 GHz receive path and the core 1 2.4 GHz receive path have dedicated on-chip LNAs. Control
signals are available that can support the use of external LNAs for each band, which can increase the receive
sensitivity by several dB.
Transmit Path
Baseband data is modulated and upconverted to the 2.4 GHz ISM or 5 GHz U-NII bands, respectively. Linear
on-chip power amplifiers are included, which are capable of delivering high output power while meeting IEEE
802.11ac and IEEE 802.11a/b/g/n specifications, and without the need for external PAs. When using the internal
PAs, closed-loop output power control is completely integrated.
Broadcom®
October 15, 2014 • 4354-DS109-R
Page 81
BROADCOM CONFIDENTIAL
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